Cushioned bearing assembly



Aug. 23, 1966 MlLLER 3,268,280

GUSHIONED BEARING ASSEMBLY Original Filed Jan. 4, 1962 INVENTOR HarveyE. Miller ATTORNEYS United States Patent Ce Patented August 23, 19663,268,280 CUSHIGNED BEARING ASSEMBLY Harvey E. Miller, Logansport, Ind.,assignor to The General Tire & Rubber Company, Akron, Ohio, acorporation of Ohio Original application Jan. 4, 1962, Ser. No. 164,361,now Patent No. 3,188,152, dated June 8, 1965. Divided and thisapplication Apr. 27, 1965, Ser. No. 451,176

8 Claims. (Cl. 308-361) This application is a division of my copendingUnited States patent application, Serial No. 164,361, filed January 4,1962, now Patent No. 3,188,152.

This invention relates to bearing assemblies suitable for use betweenrelatively rotating or oscillating parts and of the type in which atubular insert or elastic rubber is confined between a rigid bearingsleeve and a second rigid sleeve coaxial therewith and which provides acushioned support for the bearing to absorb impacts and vibration and tocompensate for misalinement of a shaft or pivot with which it is used.

The present invention provides a bearing assembly suitable for use invarious types of pivotal connections between members having relativelyoscillating movements or as a support for a rotating member thatincludes a tubular elastic rubber cushioning element and that isdesigned to protect the rubber cushioning element against torsionalstresses which would tend to cause circumferential slip between therubber and the sleeves between which it is confined. The rubber insertis preferably held under radial compression between the inner and outerrigid sleeves, the inner sleeve being a bearing sleeve provided with alow friction bearing face formed to retain a lubricant. The low frictionmaterial is preferably a resilient plastic material such as nylon,polytetrafiuoroethylene such a sold under the trade name Teflon or alinear acetal consisting of unbridged polyoxymethylene chains of greatlength such as sold under the trade name Delrin.

Reference should be had to the accompanying drawings forming part ofthis specification, in which:

FIGURE 1 is an end elevation of an assembly embody-ing the invention;

FIGURE 2 is a section taken on the line indicated at 22 in FIGURE 1;

FIGURE 3 is an end elevation showing a modification of the assembly witha portion broken away and shown in section;

FIGURE 4 is a section taken on the line indicated at 4-4 in FIGURE 3.

FIGURES 1 and 2 of the drawings show a bearing assembly that isinterposed between an outer supporting member A and an inner shaft orpivot B. The assembly comprises an outer rigid sleeve 1 which may beformed of metal, a tubular elastic rubber insert 2 that is receivedwithin the outer sleeve 1 and which is interposed between the outersleeve 1 and inner rigid bearing sleeve 3 which is formed of a materialwhich has a low coefiicient of friction, preferably a resilient plasticmaterial such as nylon, Tefion or Delrin. The bearing sleeve 3 may beprovided with radially projecting external ribs 4 which engage theinterior of the rubber insert 2 to provide an interlock and preventcircumferential slippage between the rubber and the bearing sleeve 3.Adjacent each end thereof, the bearing sleeve 3 is provided on itsinterior face with circumferential grooves 5 which form endless circularcircumferential ribs 6 between them and with internal longitudinalgrooves 7 which extend throughout the space between the end grooves 5.The longitudinal grooves 7 may be filled with lubricants and the grooves5 and ribs 6 provide a labyrinth seal at each end of the bearing.

The elastic rubber insert 2 is preferably retained under radialcompression between the outer rigid sleeve 1 and the inner bearingsleeve 3. The bearing assembly is designed to be capable of convenientassembly by methods now in common use such as disclosed in the patent toBeck, 2,660,780, granted December 1, 1953. The rubber insert 2 may becontracted and forced into the sleeve 1 by forcing it through afunnel-shaped guide which has its small delivery end registered with oneend of the sleeve 1. After assembly of the insert with the sleeve 1, theinner bearing sleeve can be forced into the rubber insert 2 behind asuitable tapered pilot or other expanding means which expands theopening of the tubular insert 2 to a diameter to receive the bearingsleeve.

In FIGURES 3 and 4 of the drawings, a modification is shown in which anouter rigid sleeve 11 which is circumferential-1y continuous confines anelastic tubular insert 12 which is retained under radial compressionbetween the sleeve 11 and an inner two-part bearing sleeve composed ofan outer cylindrical member 13 which is interposed between an innercylindrical part 14 and the rubber insert 12.

The inner cylindrical part 14 of the bearing sleeve is circumferentiallycontinuous and composed of a material having a low coefiicient offriction. The part 14 is provided with radially outwardly projecting endportions 15 which are of a height corresponding to the thickness of theouter cylindrical member 13 and which receive the cylindrical member 13between them. The interior bearing face of the inner bearing part 14 isprovided with longitudinal lubricant receiving grooves 16 and with acircumferential groove 17 adjacent each end which receives a rubberO-ring 18 to provide a seal at each end of the bearing to prevent escapeof lubricant. The outer sleeve 11 and the outer part 13 of the innerbearing sleeve are preferably formed of metal and the inner part 14 ofthe bearing sleeve is preferably formed of a resilient plastic having alow coefiicient of friction such as above described. In order to permitassembly of the relatively rotatable bearing sleeve parts 13 and 14, theouter member 13 may be provided with a longitudinal split 19 whichenables it to be expanded sufliciently to permit the cylindrical member13 to be slipped endwise over the projecting portions 15 at one end ofthe inner bearing part 14 and contracted into snug engagement with theexterior of the part 14 between the end flanges 15 thereof. The parts 13and 14 are assembled prior to the assembly of the bearing sleeve withinthe rubber insert 12. The outer member 13 of the bearing sleeve may beprovided with perforations 20 into which portions of the elastic rubberinsert 12 are expanded to provide an interlock and prevent longitudinalor circumferential slippage between the insert 12 and the member 13 ofthe bearing sleeve which contacts it. The outer sleeve 11 may beprovided with an ordinary projecting flange 21 at one end for engagementwith a supporting member A to properly position the bearing assemblywith respect to the supporting member A. The rubber insert 12 and theinner bearing sleeve are both longer than the outer sleeve 11 so thatend portions 22 and 23 of the rubber insert 12 are expanded intoengagement with the ends of the sleeve 11 to hold the same againstlongitudinal movement with respect to the rubber insert.

It is to be understood that in accordance with the provisions of thepatent statutes, variations and modifications of the specific devicesherein shown and described may be made without departing from the spiritof the invention.

What I claim is:

1. A cushioned bearing assembly comprising an inner sleeve, :aconcentric outer rigid sleeve and a tubular insert of elastic rubberretained under radial compression between said sleeves, said innersleeve having an interior cylindrical bearing portion composed of a lowfriction material and adapted to bear against a shaft pivota-llyreceived in said inner sleeve, said interior portion being provided witha series of circumferentially spaced longitudinally extending lubricantreceiving grooves, sealing means intermediate the ends of said interiorportion comprising circumferential groove means adjacent said ends forretarding escape of lubricant from said assembly, and a slip preventinginterlock between the exterior of said inner sleeve and said tubularelastic insert comprising a series of integral radially projectinglongitudinal reinforcing ribs closely spaced around the circumference ofsaid inner sleeve.

2. A cushioned bearing assembly comprising an inner sleeve, a concentricouter rigid sleeve and a tubular insert of elastic rubber retained underradial compression between said sleeves, said inner sleeve comprising acontinuous inner cylindrical bearing part composed of a low frictionmaterial and adapted to bear against a shaft, said inner bearing partbeing provided with a series of longitudinally extendinglubricant-receiving grooves, sealing means intermediate the ends of saidbearing part comprising circumferential groove means adjacent said endsfor retarding the escape of lubricant from said assembly, and an outercylindrical member interposed between said tubular insert and said innerpart, said outer member being provided with perforations into whichportions of said tubular insert may expand to provide a slip-preventinginterlock.

3. A cushioned bearing assembly comprising an inner sleeve, an outerrigid sleeve coaxial therewith and a tubuwherein said sealing meanscomprises a series of circum ferential ridges and grooves formed in saidinterior face of said inner sleeve adjacent each end thereof to providea labyrinth seal at each end of the inner sleeve.

5. A cushioned bearing assembly as defined in claim 3 wherein aslip-preventing interlock is provided between the exterior of said innersleeve and said tubular elastic insert, said interlock comprising aseries of radially projecting external ribs integral with said innersleeve, said ribs extending longitudinally between the ends of saidinner sleeve to resist deformation of the inner sleeve by the compressedrubber insert.

6. A cushioned bearing assembly as defined in claim 3 wherein said innersleeve comprises an inner cylindrical bearing part which is surroundedby a split outer cylindrical member which is interposed between saidinner bearin-g part and said tubular rubber insert, said outercylindrical member being provided with perforations into which portionsof said tubular insert expand to provide slippreventing interlock.

7. A cushioned bearing assembly as defined in claim 4 wherein said innersleeve is composed of a resilient plastic having a low coeflicient offriction, said plastic being formed to provide labyrinth seals ofserrate cross section and to provide closely spaced radially projectingexternal ribs, said ribs extending longitudinally between the ends ofsaid inner sleeve to reinforce said sleeve.

8. A cushioned bearing assembly as defined in claim 6 wherein said innercylindrical bearing part has radially projecting flanges engageable withthe ends of said outer cylindrical member to prevent axial movementthereof, and wherein said sealing means comprises rubber O-rings seatedin internal circumferential grooves formed in the interior face of saidinner cylindrical bearing part adjacent the ends thereof.

References Cited by the Examiner UNITED STATES PATENTS 1,980,117 11/1934Turner 30872 X 2,127,200 8/1938 Boers-ma 308-238 2,923,579 2/1960 Scheel308-238 X FOREIGN PATENTS 1,145,882 10/1957 France.

653,982 5/1951 Great Britain.

783,221 9/ 1957 Great Britain.

847,171 9/1960 Great Britain.

DAVID J. WILLIAMOWSKY, Primary Examiner. DON A. WAITE, Examiner. L. L.JOHNSON, Assistant Examiner.

1. A CUSHIONED BEARING ASSEMBLY COMPRISING AN INNEER SLEEVE, ACONCENTRIC OUTER RIGID SLEEVE AND A TUBUALR INSERT OF ELASTIC RUBBERRETAINED UNDER RADIAL COMPRESSION BETWEEN SAID SLEEVES, SAID INNERSLEEVE COMPRISING A CONTINUOUS INNER CYLINDRICAL BEARING PART COMPOSEDOF A LOW FRICTION MATERIAL AND ADAPTED TO BEAR AGAISNT A SHAFT, SAIDINNER BEARING PART BEING PROVIDED WITH A SERIES OF LONGITUDINALLYEXTENDING LUBRICANT-RECEIVING GROOVES, SEALING MEANS INTERMEDIATE THEENDS OF SAID BEAING PART COMPRISING CIRCUMFERENTIAL GROOVE MEANSADJACENT SAID ENDS FOR RETARDING THE ESCAPE OF LUBRICANT FROM SAIDASSEMBLY, AND AN OUTER CYLINDRICAL MEMBER INTERPOSED BETWEEN SAIDTUBULAR INSERT AND SAID INNER PART, SAID OUTER MEMBER BEING PROVIDEDWITH PERFORATIONS INTO WHICH PORTIONS OF SAID TUBULAR INSERT MAY EXPANDTO PROVIDE A SLIP-PREVENTING INTERLOCK.